Why don magnetic perpetual motion machines work?
Magnetic motors have a clever arrangement of magnets which keeps the motor rotating forever. Not surprisingly, whenever someone tries to build one, the motor rotates for a while and then stops — this is usually attributed to the magnets “wearing out”. These motors usually rely on using magnets as low-friction bearings, meaning the “motor” can coast for a long time, but it doesn’t supply any power. Magnetism is like gravity; you can store potential energy and get it back, but you can’t get more energy no matter what you try.
